Indicating and testing supply switch-box



P. H'. BARTLETT. 'INTJICATING AND TESTING SUPPLY SWITCH BOX.

Patented Aug. 17, 19201,

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INVENTQR' ATTORNEY.

P. H. BARTLETT. v INDICATING AND TESTING SUPPLY-SWITCH BOX.

i APPLICATION FILED JAN. 23,1915- 1,349. A

Patented Aug.

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INVENTQR WITNESSES ATTORN BY 4 P. H. BARTLETT. IND IBATING AND TESTING SUPPLY SWITCH 'BOX.

APPLICATION -F|LED JAN. 23, 1915. r 3 9 51 Patented Aug. 17, 1920.

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u1-uTEo STATES PERCY H. BARTLETT, or PHILADELPHIA, PENNSYLVANIA, ASSIGNOR, or ONE-THIRD.

PATENT OFFICE.

T0 JOSEPH B. SEAMAN AND oNE-Tmnn TO BUBLEIGH CURRIER, BOTH or PHILA- DELPHIA, PENNSYLVANIA.

INDICATING AND TESTING SUPPLY SWITCH-BOX.

Philadelphia, in the county of Philadelphiav and State of Pennsylvania, have invented certain new and useful Indicating and Test ing Supply Switch-Boxes, of which the following is a specification.

My invention relates to instruments intended to be permanently placed upon switch .boards to expedite and-simplify tests made thereon and protect test devices from accidental interference as well as intentional tampering.

The purpose of my invention is to p rovide safe, adequate and convenient testing connections for electric installations, preferably combining the connections for related parts of the same current or allied currents in the sameinstrument and maintaining thesame relative position for the parts in my switch as the other switch board equipment relatingto.correspondlng parts or currents,

A furtherpurpose of my invention is to place a pilot light or lights within a cover or, covers, preferably placing the lights affected by related currents underthe. same cover and separating .by a partition or by partitions preferably carried by the cover. I supply a separate bulls eye or opening for each light and shield each light from the bulls eye or opening of the other by the partition. The cover or covjers may .be locked where desired. a

A further purpose of my invention is to provide a permanent test device with termi nals by which instruments may be'connected and to supply it with current from trans.- former secondaries, either specially set apart for the purpose, or protected from other uses and connections whiclrwould disturb the phase relationsor electrical constants relied upon in indicating or recording the electrical energy and in making tests, protecting the switch circuits by fuses and indicating by pilot lights whether or not normal conditions prevail on the circuit.

A further purpose of my invention is to provide a test switch and connections spe- Specification of Letters Patent.

Patented Aug. 17, 1920;

Application filed, January 23, 1915. Serial No. 3,906.

cially suitable for the testing of instruments on either single phase or multiphase electric circuits.

Further purposes of my invention will appear in the specification and claim thereof.

1 have preferred to illustrate my invention by but two forms thereof, among the many which will occur to those skilled in' the art, selecting forms which are practical, eflicient and relatively inexpensive and which at the same time will illustrate th principles of my. invention,

Figure 1 is a top plan-view of one form of my invention, certain parts being removed.

Fig. 2 is abottom plan view of the form shown in Fig. 1.

Fig. 3 is a section taken upon line 33 of Fig. l, but with other parts in place which are not shown in Fig. 1.

Fig.4 is a diagram of the connections with which my invention may be used.

Fig. P is a fragmentary diagram showing modified connections.

Fig. 5 is a top plan view, corresponding to Fig. 1 but showing my invention adapted for a current having a different number of phases,

Fig. 6 is abottom plan view of the second form "of my invention.

Fig. 7 is a' section of Fig. 5 taken upon line 7 5, but with some parts added thereto.

In "the drawings similar numerals indicate like parts.

Heret'ofore no provision has been made to supply current from an adequate and proper source for testing purposes. The practice has been to make temporar 1 connections on the back of the switchboar to existing wirconsiderations in the proper and safe operation of a central station. By the use of my speciahsupply switch and'sockets, forming a test box, the labor is reduced to a minimum, and all. objectionable features of the old methods are eliminated; The work can be done with safety and the possible inaccuracies due to wrong connections are done away with, v

The text box pilot lights when burning up to full candle power indicate that the station instruments, such as watthour n1eters, power factor indicators, voltmeters, etc., are being properly supplied with normal potential and show that no inaccuracies exist from this source, which might occur due to the blowing of a primary fuse on a potential transformer or to a kindred cause. Such indications are of especial value in the case of polyphase instruments of various types, which are dependent upon voltages from more than one phase, all of the proper phase displacement.

The test box provides means for obtain ing testing currents of proper phase relations so that the various types of instruments may bereadily tested from the front of the board, or in juxtaposition to the meters or instruments.

Instead of the present slip'shod and uncertain scattered sources of current supply, of questionable phase accuracy, dependent upon their intermediate or associated use and of indefinite and too frequently insuflicient capacity and difficult or dangerous accessibility, I purpose providing transformers 1 and 2 of adequate size and having uniform phase.difference between their section, the neutral wire of the star connection being ordinarily disregarded.

In both of the forms of my switch shown,

from the back of the base for this purpose and are secured by -any suitable nuts 13. The rods extend also forwardly or upwardly from the face of the base for the retention of the cover. Corresponding nuts to are provided to secure the rods within the base. and knurled nuts 15 are supplied to engage the outer surface of the cover.

The rods are transversely drilled at lt' to IGCGIK? the wires of any lock or seal to prevent tampering with the. connections within;

In the forms shown the invention is applied to two phase and three phase circuits. respectively. The application to ditl'ereut phase numbers will be apparent from the discussion of these two examples.

The structure shown comprises generally connections for the transformer secondaries:

fuse plugs in series with the respective legs of the circuit; switches whereby these legs may be opened; terminals for the respective legs through which test apparatus may be connected; and pilot lights thrown across between the legs of the circuits to indicate the operation or interruption of the several phases making up the circuit: forming a concrete unitary structure of great utility and convenience.

Taking up the first form of my invention The switch base carries a triple-knife switch 17 having blades 18. 19 and 20 and insulating handle 21, the blades being hinged at. 22, 23 and 24 and engaging contacts 25, 2k) and 27 when in closed position: fuse receptacles 23 and 30 having shell contacts 31 and interior contacts 32; and pilot light sockets 33 and 35 having shell contacts 36 and interior contacts 37. Other forms of switch and contacts could obviously be used.

The leads from the transformer secondaries enter from the back of the base through openings 38, 39 and 40 and are connected at the front of the base to binding posts 41, t2 and 43, two of which, one in each phase, .are in electrical contact with one contact each of the fuse receptacles. through the interior contacts 32 by means of screws ll and 46 and conductor strips t7 and 49. The strips are secured to the contacts by nuts 50 engaging threaded stems 51 and 53 upon the contacts.

The screw l5 of the third binding post is connected to one of the contacts of each Stl ofthejsockets and by strips 54 and 55...,1 have shown the stripsas connected with the interior contact in each case by means of stems 56 and 58 and nuts t The shell contacts of [receptacle 28 and socket 33 are shown as in, electrical contact with conductor strip 59 and the shell contacts of receptacle 30 and socket 235 are shown as in electrical contact with conductor strip 61 to which strips the switch contacts 25 and 27 respectively are connected, The intermediate switch contact 26 is connected electrically by screw a5 with a conductor strip 62.

The insulation of tli e receptacles and sockets between the interior and shell contacts respectively consists of mica disks 63 and 64' pressed on opposite sides of the shell ends and strip 59-01 61 by washers 63spanning so the openings in the shell and stripand are held tight by nuts 50.

The hinges 22, 23 and 24ers connected to terminals 65, 66 and 67 by conductor strips 88, 09 and 70 and screws 71.

secured by screws 72 and 73 respect'1vely.

The cover 19; carries faceted, translucent lenses or bulls-eyes 74 and 76, for the lamps W and a partition 78 fitting between them and he shutting off. the li 'htlof each from the lens of the other. -Otherarrangements, as for example, apertures for the lights could be provided and the lights couldproject though the apertures if desired...

The lamps, as also fuse plugs 7 9 and cover 152 are omitted from Fig; 1 for clearness.

lit will be evident that each leg of the circuit isv protected by a fuse in series with it, shown as located between the lead and the switch, and that the pilot lights are located across between the neutral lead and the re spective legs of the circuit,-

till

Each of the ter'- minals has two separable connectmg devices Une means of reducing the number of pilot lights required though with some loss in .Jvantage, is shown in Fig. 4a where one light 83 is thrown across between the outside wires. Tn case either of the sides of the circuit is in trouble the fact will be shown this light but the side upon'which the uble occurs will not be indicated. The

. ded to be used are shown in Fig. l4.

Une use for my invention is seen in the diam ofcircuits in Fig. 4c. Here the" primry wires 80, 81 and 82 sup'ply'the' primary idings83'and 84: of transfcrmersl and 2, in whose secondary terminals 3, {l and 5 leads 0, 7 and 8 extend to. one of my wn as starting at 85, 86 and 87.

have shown in my diagram a set of in ections with which this construction is itches. The test instrument circuits are struments such as is quite ordinaril r mounted upon a power switchboard hand ing multiphase circuits, including in the set a poly- 1 phase watt meter, an amineter for eachof the sides of the circuit, an indicating watt meter for each of the sides ofthe circuit and a power factor indicator; i

The four coils of the polyphase watt meter 94am supplied, as usual, with current from transformers Wh oseprimaries are located in the two sides and across from each of the two sidesto the neutral, respectively. The transformers located in the two sides are here 88 and 89, from whose secondaries 90 and91 coils 92 and 93 receive their supply.

In the case of meter coils 95 and 9601: the watt meter 9d, I connect with the secondaries '85 and 8 1 to which my switch box is con- -watt meter 106 in series. The other coils of the indicating watt meters 105 and 106 are connected to secondaries whose primaries extend from the neutral wire to the respec- -tive sides of the circuit as usual, and I utilize the same secondary transformer coils which supply my switch, securing uniformity with the connections for my switch and for coils 95 and 96. The second coils each of the indicating watt meters are therefore connected with the neutral 97 each and with the respective wires 98 and 98.

. The power factor indicator, as usual, has one coilsupplied by a primary within the neutral wire 81, this primary 107 having a secondary 108 connected with the terminals of the coil 109. The other two coils of this indicator are grounded at one end each and have the other terminals connected, as usual, to secondaries whose primaries lie between the neutral and the respective sides of the circuit. Here again, I have connect- 'ed the ends of these two coils 110 and 111 whichare not grounded to the wires 98 and y 98, respectively, so as to supply them uniformly iiot'only with the other instruments,

The neutral' wire 97 is grounded.

I thus furnish a potential supply of uniform phase and voltage for all of these instruments and for my switch box, insure proper transformer capacity for all and avoid danger of variation duetto piecemeal transformer equipment.

I am further enabled to select primaries 83 and 84 and secondaries 84:" and 85' adapted for the particular 7 size of pilot lamps which I wish to use and the rest of the apparatus in the circuit. My box makes it difii cult to make a change in any part of the circuit. I treat other switchboard combinations similarly.

The use of a pilot lamp of different wattage consumption varies the accuracy of meters and instruments in the same circuit considerably, sometimes introducing an error of several per cent.

In making a test the test instruments are introduced in the circuit shown at 85, 86 and 87, giving potential readings comparable with the readings of other instruments in the circuit, as in previous tests, but with advantages in speed, ease and accuracy of connection and with the elimination of a number of previously fruitful sources of uncertainty, danger and error.

By providing fixed switch board test terminals for testing,.I insure connections necessary in accurately testing the apparatus used and avoid the difficulty and in some cases impossibility of finding adequate test points in the wiringand circuits and also the difficulty and danger of tracing. .them, de termining whether or notthe best to be found are suitable and the running of temporary connections through the connections already made. In switch boards whose sides have been inclosed by screening locked in place to avoid the danger of tampering, I avoid an opportunity for possible connivance between the test operator and the employees for tampering with the wiring, which would be provided if it were necessary-to unlock these screens.

In the form shown in Figs. 5, 6 and 7 the same arrangements are shown except in so far as additional construction is required for the additional fuse receptacle 29 in series with the middle switch and the additionahlamp socket 34 forming the third lamp socket utilized for the three phase arrangement; F or convenience, the binding posts 41, 42 and 43 are'located directly in front of the strips 59, and 61, necessitating the aperturing of these strips at 59, 60, 61 and insulation 41, 42, 43" for the binding posts where they pass through the apertures to connect with the strips 47, 48 and 49. The fuse receptacles and lamp sockets for the outer connections are in the same locations with respect to the strips 59 and 61 as in the first form, and the receptacle and socket for the strip 60 are similarly located with respect to the strip 60 and similarly insulated.

The connections between the interior contacts of the fuse receptacles 2S, :2?) and 30 are differently run because of the triple form required and comprise strips located in different levels or planes, '1'. 0., at diil'erent distances from the switch base. One of these strips 113' connects the stem 51 of fuse receptacle 28 with the stem 58 of lamp socket 35. The stems 52 and 53 as well as the stems 56 and 57 have been extended and spacing means, here nuts 50, used to support the strips 114 and 115 far enough away from the base so that they pass over the strip 113 without touching it, meanwhile connecting the inner contact of fuse receptacle 29 with the inner contact of lamp socket 33 and the inner contact of fuse receptacle 30 with the inner contact of lamp socket 34.

As will be seen one of the fuses is interposed between each of the binding posts 41, 42 and 43 and the corresponding or adjacent plate 59, (30, (51 or switch terminals :25, 26 and 27 and one of the pilot lights is connected between each pair of conductors representing the phases for the three-phase circuit.

The cover 12' of my second form is provided with three lenses, of which only is shown, and with two partitions 78 spacing between them. i

It will be evident that parts of my invention may be utilized without the use of all of it; that it may be used in other relations than those shown; and that other constructions may be utilized for carrying my invention out with part of the advantage at least resulting from the construction shown; without departing from the spirit and scope of my claim.

Having thus described my invention, what I claim as new and desire to secure by LettersfPatent is In a device of the character stated, a base, two pilot lights thereon, a circuit having two phases across which the two lights arc respectively connected, :1 cover protecting from unauthorized interference with the lights and means for distinguishing at a distance between the lights when one is lighted and the other is not.

PERCY H. BARTLE'IT. 

